diff --git a/src/ship/items/inventory.rs b/src/ship/items/inventory.rs
index 35cef9f..67bb356 100644
--- a/src/ship/items/inventory.rs
+++ b/src/ship/items/inventory.rs
@@ -82,6 +82,11 @@ pub enum InventoryItemAddToError {
     ExceedsCapacity,
 }
 
+#[derive(Error, Debug, Clone)]
+#[error("")]
+pub enum InventoryAddError {
+}
+
 impl InventoryItem {
     pub fn entity_ids(&self) -> Vec<ItemEntityId> {
         match self {
@@ -511,7 +516,7 @@ impl CharacterInventory {
             .nth(0)
     }
 
-    pub fn add_item(&mut self, item: InventoryItem) -> Result<(), ()> { // TODO: errors
+    pub fn add_item(&mut self, item: InventoryItem) -> Result<(), InventoryAddError> { // TODO: errors
         // TODO: check slot conflict?
         self.items.push(item);
         Ok(())
diff --git a/src/ship/items/manager.rs b/src/ship/items/manager.rs
index ff554ea..bfdcca6 100644
--- a/src/ship/items/manager.rs
+++ b/src/ship/items/manager.rs
@@ -917,7 +917,7 @@ impl ItemManager {
             entity_id: entity_id,
             item_id: item_id,
             item: ItemDetail::Weapon(weapon.clone()),
-        }));
+        }))?;
 
         entity_gateway.set_character_inventory(&character.id, &inventory.as_inventory_entity(&character.id)).await?;